Additional info: Launched in 2009 and expects to cover 120 million potential customers by year end. Has begun LTE trials.

Carrier: T-Mobile USA

Technology: HSPA+

Speed: 21 megabits per second peak, 5 to 10 megabits per second average

Additional info: Expects to cover 185 million potential customers by year-end. Plans to improve to 42 megabits per second sometime next year.

Carrier: AT&T

Technology: HSPA+/LTE

Speed: Not announced

Additional info: Plans to roll out LTE beginning in mid-2011. Is upgrading 3G network to HSPA+ in conjunction with LTE efforts.

Sources: Ovum, companies

Faster download speeds are coming to smart phones, laptops, tablets and other devices that connect wirelessly to the Internet.

And wireless operators are all jockeying for the top spot in consumers’ minds over which truly offers the biggest, fastest 4G — or fourth-generation — wireless service out there.

A year ago Sprint’s Clearwire joint venture was the first to market fast wireless service as 4G. Now all the big four U.S. wireless carriers are touting 4G — or “4G-like” offerings. In the most recent news, Verizon Wireless on Sunday unveiled its new 4G network using Long Term Evolution (LTE) technology in San Diego and 37 other U.S. cities.

For now Verizon is only selling USB data modems for laptops on the new network, promising consumers average download speeds that are up to 10 times faster than its current 3G network.

“We expect on a fully loaded network that download speeds of 5 megabits to 12 megabits per second will be the norm, and we expect 2 megabits to 5 megabits per second on the uplink,” said Tony Melone, Verizon’s chief technology officer.

Others are boasting similar speeds. Sprint/Clearwire claims 3 megabits to 6 megabits per second on average with its WiMax network. T-Mobile USA claims 5 to 10 megabits per second with its upgraded 3G network.

The truth is none of them come close to meeting the technical definition of 4G, said Chris Kissel, an analyst with technology research firm In-Stat.

“Even in optimal conditions, mobile operators are not even 1/12th of the way there,” said Kissel. “Therefore, the current claims that mobile operators are making about 4G technology are to be taken with a grain of salt.”

But this isn’t about technology standards. It’s about marketing.

The term 4G is out there in the public. And it’s getting tugged and twisted as mobile operators try to persuade consumers that they have the latest and greatest wireless network.

Wireless carriers have swung into two camps based on their network technologies. One is headed by Verizon and Sprint/Clearwire. Each has built brand-new networks to add capacity and boost speed.

The other camp is led by T-Mobile USA and AT&T, which have upgraded their current 3G networks to offer download speeds that are on par with those of Verizon’s and Sprint’s new networks.

The marketing debate obscures the good news about what’s going on with wireless technology, said Kissel, the In-Stat analyst. Networks are indeed getting much faster than they were in the very recent past.

“As recently as two years ago, most 3G (network) air links were capable of only 1 or 2 megabits per second,” said Kissel. “Each city or region is different, but in many parts of the country, Sprint, Verizon, AT&T and T-Mobile now are regularly achieving 5 to 10 megabits on the downlink.”

The tussle over what constitutes 4G grabbed headlines when T-Mobile began claiming it offered 4G service, even though it had not built a new network.

T-Mobile says it achieved download speeds on par with Verizon and Sprint by upgrading its 3G network with HSPA+ technology and by bringing fiber-optic cables to cell towers, which improves performance.

“We were pleasantly surprised at the performance level we achieved with HSPA+,” said Mark McDiarmid, senior director of engineering and operations at T-Mobile USA. “We took some time to look at how it compared to other technology, including 4G as it is marketed today in the U.S. and that was a pleasant surprise for us. So our positioning it as having 4G capability is really a recognition of the experience that consumer will enjoy on the devices.”

AT&T also has gone to HSPA+ technology on its current 3G network. It plans to begin rolling out its 4G Long Term Evolution network by the middle of next year. For now, it’s touting the fact that its existing 3G network has been upgraded.

“Our HSPA+ network and upgraded backhaul is expected to deliver speed performance similar to initial LTE deployments,” said AT&T’s Chief Technology Officer John Donovan in a statement.

It will take a few years for LTE to be everywhere, added Donovan. In the meantime, there will be handoffs between 4G and 3G networks in areas where LTE networks aren’t built yet.

“Customers of carriers who chose not to upgrade their current networks will move in and out of LTE coverage areas,” he wrote. “But as they do, they’ll experience a jarring speed degradation.”

Donovan says AT&T won’t face that problem because it has upgraded its 3G network.

Verizon says it’s aggressively building out its 4G LTE network. It expects coverage to match that of its current 3G network nationwide by 2013.

In San Diego County, Verizon’s 4G coverage today reaches about as far north as Poway. Street-level maps showing the carrier’s coverage area are available on the company’s website.

Sprint’s Clearwire service is not yet available in San Diego County.

Verizon officials point out there are other advantages to LTE besides speed. One is “latency,” which is the delay that sometimes occurs when accessing the Web. Latency is important in syncing audio and video in video conferencing. It also is important for mobile online gaming.

Both Verizon and Sprint/Clearwire say the extra capacity in their new networks is vital as mobile data traffic continues to surge with more people accessing the Web and streaming video to smart phones and tablets.

“When it comes to mobile broadband, speed is important, but capacity is king,” said Mike Sievert, chief commercial officer for Clearwire, in a post on the Internet.

Right now, there’s not a killer application that taps the speed and capacity of these new networks, said Melone, Verizon’s chief technology officer.

But he thinks such applications are coming soon, especially ones with video.

“You can imagine the kind of work the app developers will do to take advantage and leverage a network with this kind of performance,” he said.